Hi, I'm using the latest version of Acymailing 5 and we're encountering a problem where the smart newsletter won't generate.
Whilst working through trying to solve the issue we've also found that the previews of the smart newsletter don't generate and result in a screen as per the image below:

When looking in the logs I'm seeing a 500 error for POST /administrator/index.php?option=com_acymailing&ctrl=autonews HTTP/1.0
Are you able to point me in the right direction for solving this?
Thank you
KH